OBJECTIVE: To assess the impact of new preventive measures of surgical site infections after coronary artery bypass graft (CABG) surgery. METHOD: A retrospective study of 468 patients who underwent CABG surgery with cardiopulmonary bypass was performed. These patients were distributed into two groups: Group A (n=224) and Group B (n=244), respectively before and after a new protocol. The two groups were compared by statistical analysis to determine differences in risk factors, the incidence of sternotomy surgical site infections (superficial and deep), recurrent infections and hospital readmission. RESULTS: There was a greater use of internal thoracic artery grafts (p=0.003) and a shorter time of mechanical ventilation (p=0.001) in Group B. Surgical site infections occurred in 44 patients of Group A (19.6%); 33 superficial (14.7%) and 11 deep (4.9%) while in Group B only 13 patients had this complication (5.3%); 10 superficial (4.1%) and three deep (1.2%) surgical site infections. Significant improvements were seen in the total number of surgical site infections (p<0.001), of superficial infections (p<0.001) and of deep infections (p=0.037). There were 36.3% and 7.7% of recurrent infections in Groups A and B, respectively (p=0.102). Hospital readmissions due to surgical site infections were 21 in Group A and three in Group B (p<0.001). CONCLUSION: The new preventive measures and treatment for surgical site infections after CABG surgery in this series of patients, significantly reduced the incidence of sternotomy surgical site infections and hospital readmissions related to this complication.